【作者】 李宏涛；

【导师】 卢双舫；

【作者基本信息】 大庆石油学院 ， 矿产普查与勘探， 2004， 硕士

【摘要】 我国碳酸盐岩普遍有机质丰度低且以高过成熟为主，对其气源岩的评价不仅不适宜直接采用国内已有泥质气源岩的评价方法，也不能照搬国外较低成熟度碳酸盐岩气源岩的评价方法，然而，对气源岩的评价事关我国对天然气的勘探方向和投资力度，因而具有极其重要的现实意义。 由于所生成的气态烃只有从源岩中以游离相运移出来之后才能对气藏的形成做出贡献，因此对气源岩的排气能力的评价显得犹为关键。本文根据物质平衡法原理将比较棘手的排气态烃问题，分解成相对较易考察的生气态烃问题和残留、耗散气态烃的问题，以排气量大小(排气量=生气量—吸附气量—油溶气量—水溶气量—扩散气量)为评价碳酸盐岩气源岩标准。 本文以塔里木盆地地质参数为例，计算了不同地质条件下气源岩的生气量、残留气态烃量、吸附气量、油溶气量、水溶气量、扩散气量，进而根据物质平衡法计算出排排气量。建立了不同厚度、不同生烃潜力、不同顶面埋深条件下烃源岩的有机质丰度理论下限、工业下限及分级评价标准。 具体的主要研究内容及成果如下： 1．提出以物质平衡原理为理论基础，以排气态烃量的有无和大小来对碳酸盐岩气源岩进行定量计算分级评价的研究思路。 2．以塔里木盆地为例建立了碳酸盐岩气源岩理论下限和工业下限评价标准。分别计算了不同地质条件下单位面积碳酸盐岩的生气量及源岩和围岩各种形式的残留和耗散气量(吸附气量、油溶气量、水溶气量、扩散气量)，进而根据物质平衡原理计算出气源岩开始以游离相有效排气时所对应的有机碳含量，并将它作为该地质条件下气源岩的有机质丰度理论下限值。 3．基于排气强度的大小确定了气源岩分级评价标准，并计算了相应的有机质丰度界限值，绘制了塔里木盆地碳酸盐岩气源岩有机质丰度分级评价图版。经过分析综合，归纳出我国碳酸盐岩沉积区(Ⅱ型有机质，成熟碳酸盐岩)气源岩有机质丰度分级评价标准。 4．把实际扩散气量与最大扩散气量的概念区别开来，并分别进行计算。研究表明最大扩散气量可能是实际扩散气量的几倍甚至几十倍。以往用最大扩散气量来代替实际扩散气量的算法会过高的估计天然气的扩散损失量，给气源岩评价和气藏的资源评价带来较大的误差。 5．考察了碳酸盐岩有机质成油、成气及油裂解成气动力学行为，并根据实验结果对动力学模型进行了标定，使得定量、动态的计算碳酸盐岩烃源岩的生气量成为可能。 6．根据计算结果对碳酸盐岩气源岩有机质丰度下限的影响因素进行探讨。更多还原

【Abstract】 In China, Most of carbonate source rocks are low organic enrichment and high-maturity, over-maturity, therefore, neither does the existing assessment method of argillaceous gas source rocks in China fit for the evaluation of this sort of source rocks, nor can copy the foreign evaluation of lower maturity carbonate gas source rocks.the value of carbonate gas source rocks is an important thing that determines the investment and oriention of exploration.Since the generated gas from gas source rocks is expelled in the form of separate phase, can it be useful for the form of pool.so,the expelling gas value of carbonate gas source rocks is more important, this paper, based on the principle of material balance, divide the tough problem of expelling hydrocarbon into relatively and easily investigated problems of gas hydrocarbon generation, residual and diffusion gas hydrocarbon and evaluate gas source rocks in temis of the magnitude Of expelling gas; hydrocarbon(quantity of expelling gas= gas quantity of generation-adsorption-dissolving in oil-dissolving in water-diffusion).This paper take the conditions of Tarim as an example, calculate quantity of gas generation, residual gas hydrocarbon, gas adsorption, gas dissolving in oil, gas dissolving in water, and gas diffusion under different geologic conditions, then according to the principle of material balance, work out gas expelling quantity. Lastly establish theoretical, industrial threshold value of organic enrichment of source rocks and grading evaluation criterion under different source rocks thickness, hydrocarbon potential, superface depth conditions.The main content and achievements are listed as following: .1. put forward a new research approach which uses the principle of material balance as the theoretical basis, and quantificationally make grading estimation of carbonate gas source rocks by the quantity of hydrocarbon expelling.2. take Tarim basin as an example to establish theoretical, industrial threshold value of organic enrichment of carbonate gas source rocks. Calculate gas quantity of generation, adsorption, dissolving in oil, dissolving in water, diffusion of unit area carbonate rocks at different geologic conditions. And then according to the material balance principle, figure out the corresponding organic carbon content when gas being started expelling from source rocks with separate phase. Regard it as the theoretical threshold value (TOCmin) of gas source rocks at that same geologic condition.3. set up grading estimating criterion of gas Source rocks with the gas hydrocarbon expelling intension. Figure out the corresponding organic carbon content threshold value, and plot grading estimating plates of oil and gas carbonate source rocks in Tarim basin. Through anasynthesis, sum up organic enrichment grading estimating standard of oil source rocks and gas source rocks in our country (type II organic matter, mature carbonate rocks).4. distinguish the concepts of gas actual diffusive flux and maximal diffusive flux; and calculate respectively. We find that maximal diffusive flux can be several times even scores of times larger than actual diffusive flux. Using maximal diffusive flux to substitute actual diffusive flux, which will overestimate diffusion losing and bring biggish error for estimate of gas source rocks and resource evaluation of gas pool.5. Study kinetics behavior of oil generation, gas generation from organic matter in carbonate rock and oil to gas. And calibrate kinetic models using experimental data. Make it possible to calculate quantity of oil generation, gas generation from carbonate source rocks quantificationally and dynamically.6. According to the results of calculation,discuss the effect factor of Threshold value of of organic enrichment.更多还原